I upgraded a computer from Linux Mint 18.3 Sylvia to Linux Mint 19 Tara and now BOINC will not run GPU WUs any more. I'm running BOINC 7.12.0. The only Notice is:

Milkyway@Home: Notice from BOINC
Your current settings do not allow tasks from this project. To fix this, you can change Project Preferences on the project's web site.
Tue 17 Jul 2018 12:14:47 AM PDT

Anyone know how I can get GPUs working again???
BTW, it took several hours to upgrade to Linux 19. NoMachine works so much faster on this headless computer than Linux 18.3 which was unbearably slow.
I don't recommend upgrading until more kinks get worked out.
Tried Folding@Home 7.5.1 & it DLs WUs but shortly after they start running they fail and another WU is DLed. All 3 1080 Ti's do the same. I have all the latest updates and the latest Nvidia driver.

I believe I fixed it.
First: Linux 19 does not default to include recommended dependencies. Fix with 1.2.1: https://sites.google.com/site/easylinuxtipsproject/mint-cinnamon-first
Second: Install CUDA: https://help.ubuntu.com/community/Cuda